Variable-capacity rotary-vane pump



Nov. 5, 1957 c. D. ROBINSON, JR 2,811,926

VARIABLE-CAPACITY ROTARY-VANE PUMP Filed Aug. 8, 1956 2 Sheets-Sheet lFIGJ I 5 lav/ INVENTOR GEORGE D.- ROBINSON ,JR-

@ ATTORNEYS Nov. 5, 1957 G. D. ROBINSON, JR 2,811,926

VARIABLE-CAPACITY ROTARY-VANE PUMP 2 Sheets-Sheet 2 Filed Aug. 8, 1956FIG". 4

FIC3-5 INVENTOF? GEORGE D- ROBINSON, JR

W4 *M. BY ATTORNEYS United Sttes Patent ffice 2,81 1,926 Patented Nov.195 7 2 8113926 VARIABLE-GAPACITY ROTARY-VANE. PUMP George D. Robinson;In, Agawam, Mass assignor to Gilbert & Earlier Manufacturing Company,West Springfield} Massi; a corporation: of Massachusetts- ApplicationAugust 8,. 1956,. Serial No. 602,788

I Claim. (CF. 3 -1216) This invention relates to improvements invariablecapacity pumps of the rotary-vane type.

The invention has for its object the provision of improved means forshifting the cylinder of the pump from active pumping position toinactive pumping position by the application of hydraulic pressure tothe external surface of the pump cylinder without necessitating theformation of aspecial cylinder in the pump housing and a piston for thepurpose.

This invention will be disclosed with reference to one illustrativeembodiment of it in the accompanying draw ings, in which 7 i i V I Fig.1 is an elevational view, partly in longitudinal sec tion, of arotary-vane-type pump embodying, the invention;

Fig. 2 is a cross sectional view taken ou the line 2-2 of Fig. 1,showing the pump positioned for pumping at the maximum rate;

Fig. 3 is a' View, taken simi-lar lyto Fig. 2 but showing the pump innon pumping-posit-iongg j Fig. 4 is a sectional plan-view t'alien' onthe l'i'n'e 4 -4 of Fig. 2;

Fig. 5 is a cross sectional view taken on the line 5-5 of Fig. 1; and

Fig. 6 is a fragmentary sectional view taken on the line 6-6 of Fig. 2.

Referring to these drawings; the rotary pump has been shown in one ofits adaptations, namely, for the purpose of priming a centrifugal pump.The latter has been shown in part only as the invention is not limitedto this one specific use. However, the complete centrifugal pump and theconnections between it and the rotary pump are fully disclosed in theAlfred L. Grise Patent No. 2,612,844, granted October 7, 1952, to theassignee of the present invention. Reference to this patent may be hadfor a complete disclosure of the centrifugal pump it necessary ordesired.

The rotary pump of this invention includes an outer housing which iscomposed of two side wall members 1 and 2 and an intervening annularmember 3, which affords a peripheral wall surrounding a chamber 4, theend walls of which consist of the inner fiat faces of the side wallmembers 1 and 2. The peripheral wall of chamber 4 is composed of twoopposed semi-cylindrical surfaces 5 and 6, the axes of which arerespectively indicated at 5 and 6', and intervening connecting grooves 7and 8, herein shown as semi-cylindrical in form. The groove 8 receives afulcrum pin 9 which is engaged in a similar groove 1% in the stator 11of the pump.

This stator is of hollow cylindrical form with coaxiallydisposed innerand outer cylindrical surfaces 12 and 13. Its ends abut the inner fiatfaces of the side walls 1 and 2. A plunger 14, slidably mounted in adrilled hole in wall 3, is urged radially inwardly by a spring 15,bearing on the top of stator 11 and tending to move it downwardly into afirst position wherein substantially all of the lower half of itscylindrical periphery 13 abuts and tightly fits the lowersemi-cylindrical surface 6. The stator is movable upwardly to asecondposition in which substantially allot the upper half of its cylindricalperiphery abuts and closely fitsthe semi cylindrical surface 5.Recesses- 16 and 17 are formed in; the upper and lower periphery ofstator 11 and these become closed when the stator is moved into itssecondand first-named positions, respectively, as will be clear fromcomparing. Figs. 2 and 3. Itwill be clear that there is 'nocommunication between these recesses 16 and 17.- v

v The pump rotor 18 is of the Well known vane type. It iscylindrical inform and provided with a circular series of angularly-spacedradiallydisposed vanes 19 which are sl-idably mounted in slots formed in therotor. The ends of the rotor have annular recesses 20 therein, which receive one in each, rings 21, supporting the ends of all the vanes andholding their outer edges engaged with the inner cylindrical wall of thestator. When the stator is in its first-or lowermostposition the. axesof the rotor and stator. are not coaxial and the rotor is positioned forpumping at the maximum rate.- When the rotor is in its second oruppermost position the rotor and stator are coaxial and no pumpingoccurs. The rotor 18 is suitably figred, as indicated, to a drivingshaft 22 which is suitably supportedin the same way as disclosed in theabove-named Grise patent, in a sleeve bearing 23' fixed in sidewallmemberand by other bearings contained in thehollow membe; 24;

This' member the side; wall member 1, the pe= riplieral 'wall member}and side wall' member 2 are suitablyclamped together as" for example, bya series of cap screws 25' whichpass through holes in the severalmembers and thread into the member 2' which forms a side wan of thecentrifugal pump lfou'sirfgi. The. im eller of the centrifugal pump isshownin' part at 27 and has a series of" lioles 28 tlierein', throughwhich fluid may be drawnfrmn radiar Inca dens near the'ihret eyeof thehous ing into the inlet port of the rotary priming pump.

The inlet and outlet ports of the rotary pump are marked 29 and 30 andthey are respectively formed in the side wall members 2 and 1 (Fig. 6).These ports 29 i and 30 are in the form of arcuate slots which areseparately shown in Figs. 2 and 5, respectively. The slot 29communicates with all the holes 28 in the impeller and the slot 30 isconnected by means in part at 31 in Fig. 4 and fully disclosed in theGrise patent, to the outlet of the centrifugal pump. Of course, if therotary pump is not to be connected to a centrifugal pump, these slotswill be suitably covered except for the necessary inlet and outletpassages. The inlet port 29 is in continuous communication with therecess 16 in member 11 by means of a radial hole 32 (Figs. 2 and 6)formed in said member. The outlet port 30 is in continuous communicationwith the recess 17 by means of a second radial hole 33 (Fig. 6) formedin member 11.

In operation, assuming the parts to be positioned as in Fig. 2 and therotor to be revolving counterclockwise, fluid, initially air, will bedrawn from the eye of the impeller through the passages 28 and the inletport 29 into the cylinder 11 and the spaces between successive blades 19and carried to the outlet port 30 and expelled therefrom through passage31, all in the usual and well known manner. No substantial pressure willbe built up until the air has been eliminated. Liquid is then drawn inby the pump and pressure builds up. When sufficient pressure builds up,then the pump cylinder 11 is to be moved by such pressure into itsinactive position shown in Fig. 3. To some extent, this cylinder may bemoved by the differential pressure within the cylinder because there isa greater area exposed to such pressure in the space that lies above ahorizontal plane passing through the axis of the fulcrum 9 than there isbelow such plane. However, this invention also provides for pressureoutside the cylinder in order to get a greater force to more quicklymove the cylinder 11 from one extreme position to the other. While thishas been done before by a piston and cylinder arrangement, such forexample, as shown in the abovenamed Grise patent, the result isaccomplished here in a different and better manner. Note that in Fig. 2,there is a chamber formed between the three walls of recess 17 and thewall 6 of member 3. This chamber is sealed off from the other recess 16and is closed completely except for its connection 33 with the outletport. The upper half of cylinder 11 is subjected to inlet pressurethrough the hole 32. The differential of these pressures is available,acting over a large area of the cylinder to raise the latter againstspring 15 and move it into its upper and inactive position shown in Fig.3. Thus, in effect, the cylinder functions also as a piston and therecess 17 as a cylinder for the purpose of moving the cylinder 11 toinactive position. As the cylinder 11 is moved upwardly, it presents anincreasing area to the outlet pressure while the area subjected to inletpressure diminishes, thus accelerating the movement of the cylinder intoits inactive position. When the outlet pressure drops sufliciently, thecylinder 11 will be moved back into the Fig. 2 position by spring 15.Thus, a very elfective way of moving the cylinder 11 is provided and onewhich is exceedingly simple and can'be manufactured at relatively lowcost due to the simplicity of the machining operations. The member 3 isbored from one axis, as and then moved slightly and bored again aboutthe axis 6'. The recesses 16 and 17 may be cast in the periphery of thecylinder and the passages 32 and 33 are simple drilled holes.

The invention thus provides an improved arrangement for shifting thecylinder of the pump from active pumping position to inactive pumpingposition by the application of hydraulic pressure to the externalsurface of the cylinder without necessitating the provision of aseparate cylinder and piston in the pump housing for the purpose.

What is claimed is:

In a rotary-vane variable-capacity type pump, having an outer housingconsisting of a pair of side wall members and an interposed memberafiording a peripheral wall surrounding a chamber, the ends of which areformed by the inner faces of said side wall members, the peripheral wallof said chamber composed of two opposed semicylindrical sections theaxes of which are spaced apart and two outwardly extending grooves, eachinterconnecting the adjacent ends of two semi-cylindrical sections, astator comprising a hollow cylindrical member having coaxial inner andouter surfaces, 3. fulcrum for said stator mounted in one of saidgrooves, a spring-pressed plunger mounted in the peripheral wall of thehousing tending to hold the stator in a first position, wherein one halfof its outer cylindrical surface abuts one semi-cylindrical wall of saidchamber, a rotor mounted within the stator and having radially movablevanes the outer edges of which engage the inner cylindrical wall of thestator, said rotor being disposed eccentrically of the stator when thelatter is in said first position, and concentrically of the stator whenthe latter is in a second position wherein the other half of its outercylindrical wall abuts the other semicylindrical wall of said chamber,said stator having diametrically-opposed recesses extending part wayonly around its periphery, said recesses being closed by saidsemi-cylindrical walls one when the stator is in said first position andthe other when the stator is in said second position, said ends of saidchamber having therein inlet and outlet ports communicating with thespaces between the stator and the rotor and its vanes, said hollowcylindrical member having therein passages one connecting one of saidrecesses to the inlet port and the other connecting the other of saidrecesses to the outlet port.

References Cited in the file of this patent UNITED STATES PATENTS2,433,484 Roth Dec. 30, 1947 2,451,666 De Lancey Oct. 19, 1948 2,612,844Grise Oct. 7, 1952 2,633,805 Haugdahl Apr. 7, 1953 2,742,861 OConnor eta1 Apr. 24, 1956

